you need to add +9 +9-7 = +2
nine add 7 to get from -7 to 0 then add 2 to get to 2 7 + 2 = 9
1+3+5+7+9+7+9+9
factor OS 63 63 - 1, 3, 7, 9, 21, 63 7 and 9 add up to 16 7+9=16
9 10ths
you need to add +9 +9-7 = +2
It is: -9+16 = 7
nine add 7 to get from -7 to 0 then add 2 to get to 2 7 + 2 = 9
7 add 7 add 7 then you take away 12
1+3+5+7+9+7+9+9
factor OS 63 63 - 1, 3, 7, 9, 21, 63 7 and 9 add up to 16 7+9=16
(7 x 9) + 20 = 63 + 20 = 83
-7
16
-61
9 10ths
9 tenths